Method and filling system for pressure-filling containers

ABSTRACT

The invention relates to a method for pressure-filling bottles, cans or similar containers ( 2 ) with a liquid filling material. In said method, for the filling process against a clamping or filling pressure (PI), the container arranged during the filling process in a sealed position against a filling element ( 6 ) is pre-pressurised by means of an inert gas, for example CO 2  gas, to the clamping or filling pressure in at least one treatment phase and, after filling, in at least one further treatment phase, is relieved of pressure to ambient pressure, wherein the treatment duration and/or time of at least one treatment phase is determined by a timing control, and wherein a pressure-measuring device ( 14 ) detects the pressure profile ( 16 ) of the internal pressure of the container at only one filling element ( 6 ), and all filling elements of the filling element group are monitored and/or corrected using said pressure profile.

The invention relates to a method according to the preamble of patent claim 1 and to a filling system according to the preamble of patent claim 7.

Method and filling systems for pressure-filling, i.e. for filling bottles, cans or other containers with a liquid filling material under counterpressure (clamping or filling pressure) are known in different versions. These methods have in common that the particular filling process has at least two treatment phases in which the particular container is arranged in a sealed position pressed against the filling element concerned, namely a preparation phase in which the container interior is pre-pressurised by means of an inert gas, e.g. CO₂ gas, to the clamping or filling pressure, and a filling phase in which the actual filling of the container with the liquid filling material is performed under counterpressure. The filling is followed by a relief phase in which the interior of the container is relieved of pressure to ambient pressure, wherein the relief is preferably performed in at least two stages, first to a pre-relief pressure and then to ambient pressure.

Usually, the filling process features still further treatment phases, for example at least one treatment phase or evacuation phase in which the particular container interior is evacuated, and/or at least one treatment phase or rinsing phase in which the particular container interior is rinsed with the inert gas, e.g. CO₂ gas, wherein several alternating, successive evacuation and rinsing phases can also be used. Furthermore, individual treatment phases can feature several partial phases, e.g. the filling phase can also have partial phases for slow priming, for fast filling, for slow residual filling and for steadying the filling material etc.

In known methods and filling systems, the initiation and termination of essential treatment phases is time-controlled, i.e. with treatment times specified for the individual treatment phases whose start, for example, is machine-controlled and/or whose duration (beginning and/or end) is saved and/or entered in the controller (computer) of the filling system, for example, also in a product- and/or container-specific manner.

The selection or setting of the treatment times and/or their durations for the individual treatment phases is usually performed on the basis of values gained from experience, wherein the switching times shall also be taken into account which are required for opening and closing the valves controlling the treatment media during the treatment phases. One disadvantage of this is that the actual sequence of the treatment phases is not monitored and the setting heavily depends on the experience of the particular operating staff and that even the smallest lack of attention and/or inaccuracies can lead to a reduction in the quality of the filled product and/or to an increase in the consumption of inert gas or CO₂ gas and thus to increased operating costs.

A method and a filling system for pressure-filling containers (DE 100 08 426 A1) are known. The aims include monitoring and/or diagnosing the individual filling elements during the running filling process, in order to detect a malfunction of the filling elements early and to be able to initiate countermeasures. This requires the provision of a separate pressure sensor, at each filling element, for measuring the pressure profile.

Also known is a filling system for pressure-filling containers (DE 100 08 426 A1). The aim is to optimise the duration of the relief phase upon completion of the actual filling process. This includes, for a plurality of filling elements, the provision of a pressure sensor at a filling element with which the pressure profile of the internal pressure of the container during the relief phase is detected and the length of time of the relief phase for all filling elements of the filling system is defined.

The invention is based on the task of avoiding the above-mentioned disadvantages and to create, in a method for pressure-filling containers, a possibility of objectively checking and/or monitoring the treatment phases and their sequence, in particular also with the possibility of optimum adaptation of the treatment times to actual requirements. To solve this task, a method according to patent claim 1 has been designed. A filling system is the subject of patent claim 7.

In the context of the present invention, the term “pressure profile” means that the level of a pressure is measured or ascertained at short time intervals so that, finally, the actual values of this pressure over time and also the changes of the actual value of this pressure over time are known too.

The invention, inter alia, is based on the finding that the pressure profile of the internal pressure of the particular container located in a sealed position with the filling element during the filling process contains all the required information about the sequence of the individual treatment phases, i.e. this pressure profile provides information on whether the filling process or its treatment phases proceed or have proceeded in the desired manner, in particular also taking into account the factor that, especially for more complex filling processes or filling methods such as the low-oxygen filling of beer or the filling of other products containing CO₂, the pressure profile in the particular container not only enables complete tracing and/or monitoring of the individual treatment phases but, in particular, also materially affects the quality and shelf life of the filled product. Thus, for example in a more complex filling process with preceding evacuation and CO₂ rinsing phases, the correct sequence of these phases is critical both for the subsequent CO₂ concentration and also for the oxygen content in the filling material filled and thus for the shelf life of the filling material filled.

The invention has the major advantage that the filling process, but also the quantity and/or composition of the gases located in the particular container and thus, in particular, the CO₂ and oxygen content, can be determined and calculated relatively accurately, by taking into account the pressure profile of the internal pressure of the container and by applying, for example, the equation of state for (real) gases P*V=m*R*T. Thus, for example, it can be easily determined which composition the gas located within a container has after the individual treatment phases, for example after the first, second and third pre-evacuation in connection with a first and second rinse with pure CO₂ gas. The invention also enables the optimum design of the particular filling process, especially regarding the consumption of inert gas or CO₂ gas and, for this purpose, the easy consideration of different container volumes, in particular to ensure a low oxygen intake or concentration in the filling material, with the lowest possible CO₂ consumption.

However, to keep the measurement and control requirements as low as possible, in terms of both hardware and software, the filling positions of the filling system form at least one group with several filling positions to which a filling position with a pressure-measuring device is then allocated, e.g. for common monitoring, setting and/or correction of the treatment times of all filling positions of this group. Due to the pressure profile measured, it is then possible to make statements regarding the sequence of the treatment phases at all filling positions of the group and/or a correction and/or change of the treatment time (also regarding start and/or duration) of one or several treatment phases, the latter e.g. by comparison of the measured pressure profile as an actual pressure profile with a specified or saved nominal pressure profile or with corresponding nominal values. This change or correction is then performed such that, by changing the start and/or the end of the particular treatment phase, the required internal pressure of the container for this phase can be obtained. This setting and/or correction of the treatment times, for example, is performed manually or by machine and/or for all filling positions of the group.

If the filling system is a filling machine, for example a filling machine of a rotary construction, then, for example, only one filling position or one filling element or only two filling elements diametrally opposed in relation to a machine axis with a pressure-measuring device detecting the internal pressure of the container, will be implemented. The treatment times of all filling elements are then changed and/or corrected according to the pressure profile of the internal pressure of the container detected by these measuring devices.

In detail, the control or regulation of the treatment time, for example, is performed such that, in the machine control of the filling system, a valid, i.e. product- and container-specific nominal pressure profile is saved for the particular filling material or product to be filled and for the type of the containers to be filled, together, if required, with nominal control times for the valves controlling the individual treatment phases of the filling process, wherein these nominal control times, for example, are based on values from the past. During the running filling process, the at least one pressure-measuring device is used to detect the pressure profile of the internal pressure of the container at the filling position concerned, at least intermittently as an actual pressure profile. Taking into account this actual pressure profile and the nominal pressure profile or corresponding data, the making of a statement regarding the sequence of the treatment phases is then possible, as well as a setting and/or correction of the treatment duration and/or treatment times, i.e. the current points in time and time intervals for opening and/or closing the valves controlling the individual treatment phases, also for those filling positions which do not have the pressure-measuring device.

Preferably, there is a continuous detection of the actual pressure profile, wherein any required corrections or changes of the treatment times are continuously ascertained and used for the selection of the filling positions.

In a preferred embodiment, the pressure profile ascertained by the at least one pressure-measuring device continues to be stored in a computer, preferably in the computer controlling the filling system, so that this pressure profile can be shown on a display or operator screen at any time.

It is also possible, in particular, to provide software limit values for the monitoring of the actual pressure profile. Exceeding and/or going below them first causes the change or correction of the treatment times and/or triggers alarm functions and/or error messages.

If the relief phase is also monitored analogously, then the advantage of the invention is especially obvious for such filling systems or filling machines in which, to save a further gas channel or ring channel at the rotor, the residual relief is performed directly in a ring channel serving as a vacuum channel. In these filling systems, a very careful setting of the treatment duration or relief duration is necessary, as exceeding the treatment duration even for a short time leads to an insufficient pressure or even to a vacuum and thus to an unwanted foaming of the filled product in the container. In the invention, this set of problems is solved in that the treatment duration of the residual relief phase can be set very accurately, taking into account the pressure profile detected by the pressure-measuring device, without difficulty.

In a particularly advantageous manner, the invention further provides that the measured pressure profiles are or the corresponding data is transmitted over a communication network, for example over an internal or external communication network, e.g. transmitted over the general Internet or the associated server(s) to at least one workstation or computer within the company operating the filling machine or the filling system and/or to a location geographically distant therefrom, preferably for remote maintenance and/or diagnostics, especially also by specialists, e.g. by specialists from the manufacturer of the filling machine or the filling system.

Further developments, advantages and possible applications of the invention also follow from the description below of execution examples and from the Figures. For this purpose, all features described and/or pictorially represented, for themselves or in any combination, in principle, are subject of the invention, irrespective of their summary in the claims or their retrospectivity. The content of the claims is also made a part of the description.

Below, the invention is clarified using the Figures by means of an a execution example, showing

FIG. 1 in a simplified schematic diagram: a filling position of a filling machine for pressure-filling containers in the form of bottles, together with a process computer for controlling the treatment times;

FIG. 2 in a diagram: the pressure profile within a bottle during the filling process involving several treatment phases.

In the Figures, 1 is a filling system or a filling machine for pressure-filling containers in the form of bottles 2 with a liquid filling material which, for example, contains CO₂, e.g. drink, for example beer. Of the filling machine, only a section through a ring bowl 3 is shown, which is part of a rotor 4 which is rotatably drivable about a vertical machine axis. The interior of the ring bowl 3 is partly filled with the liquid filling material during the filling operation, by forming a lower liquid space 3.1 taken up by the filling material and a gas space 3.2 above taken up by an inert gas under pressure, for example a CO₂ gas under pressure. By means of regulation and/or control elements (not shown), the level of the liquid filling material in the ring bowl 3 is set or controlled to a specified level. Furthermore, the inert gas pressure is set or controlled in the gas space 3.2 to a specified filling or clamping pressure P1.

In the rotor 4 or in the part of the rotor 4 that forms the ring bowl 3, two ring channels are also formed, namely a ring channel 5.1 which serves as an inert gas collection channel and guides the inert gas with a pressure P2, e.g. with a slight excess pressure, as well as a ring channel 5.2 which, during the filling operation as a vacuum channel, has a vacuum P3.

At the circumference of the rotor or the ring bowl 3, filling elements 6 are provided distributed at equal angular distances about the vertical machine axis which, always together with an associated container carrier 7, form filling positions 8. The bottles 2 to be filled are each held suspended at the individual filling positions 8 or at the local container carriers 7, namely at a container flange or mouth flange and with the container carrier 7. With this, the bottles 2 are pressed in a sealed position against the particular filling element 6 in the area of a discharge port 9 for the liquid filling material as well as a gas port 10 for evacuation, pre- and pressure-clamping, as clarified below.

For the controlled discharge of the liquid filling material into the particular bottle 2, a liquid channel with controlled liquid valve, said liquid channel being connected with the liquid space 3.1, is provided in each filling element 6. Furthermore, in each filling element 6, gas routes are provided for the controlled treatment of the interior of the particular bottle 2 with vacuum, with rinsing gas and pre-clamping gas, for the control of slow and quick filling phases, for the relief of the particular filled bottle etc. The valves necessary for the control of these gas routes are housed in a valve block 11. These valves, for example, are pneumatic valves selected via an electro-pneumatic control valve arrangement 12 by a computer 13.

Only a filling position 8 or the local filling element 6 is equipped with a pressure-measuring device in the form of a pressure sensor 14 which, via the gas port 10, during the particular filling process, detects the internal pressure of the bottle 2 located at this filling element 6 and supplies a corresponding measurement signal via the measurement line 15 to the computer 13, namely for creating and saving the pressure profile 16, over time, of the internal bottle pressure of the bottle 2 located at the filling element or of a corresponding data record.

The filling of the bottles 2, in principle, is performed such that each bottle 2 is handed over at a container infeed of the filling machine 1 to a container carrier 7 and, with this container carrier, then pressed in a sealed position against the associated filling element 6 or with its bottle mouth against a seal of the filling element 6 arranged in the area of the discharge port 9 and the gas port 10, so that both the discharge port 9 and the gas port 10 are connected with the interior of the bottles 2. The filled bottles 2, having been lowered with the container carrier 7 from the filling element 1, are removed at a container outfeed of the filling machine 1, for example delivered to a closing machine.

In the angular range of the rotary motion of the rotor 4 between the container infeed and the container outfeed, the filling of the bottles 2 is performed in several treatment phases, for example one after the other

-   -   a triple evacuation by connecting the interior space of the         bottles with the ring channel 5.2, always with an inert gas         rinse of the interior space of the bottles between the first and         second or the second and third evacuation, e.g. by connecting         the interior space of the bottles with the ring channel 5.1,     -   a partial pre-clamping of the bottle 2, e.g. by connecting the         interior space of the bottles with the ring channel 5.1 and/or         with the gas space 3.2,     -   a pre-clamping of the bottle 2 by connecting the interior space         of the bottles with the gas space 3.2 to the final clamping or         filling pressure P1,     -   a fast filling of the bottle 2 with the liquid filling material         from the liquid space 3.1 with opened liquid valve at clamping         and filling pressure P1,     -   a slow filling of the bottle 2 at clamping and filling pressure         P1 prior to closing the liquid valve and shortly before reaching         the required filling level and/or filling quantity,     -   a steadying of the filling material in the bottle 2 at         pre-clamping and filling pressure P1 and with closed liquid         valve,     -   a pre-relief of the bottle 2 at a pre-relief pressure         substantially below the clamping and filling pressure P1, for         example to the pressure P2,     -   a subsequent residual relief to atmospheric or ambient pressure,         for example by connecting the part of the interior space of the         bottle not taken up by the filling material via the gas port 10         with the ring channel 5.2.

FIG. 2 also schematically shows the pressure profile 16 detected by the pressure sensor 14 at the filling element 6, wherein the sections 16.1-16.9 need to be allocated:

-   -   16.1 Start of the filling process     -   16.2 Pre-evacuation of the bottle 2     -   16.3 Inert gas rinsing of the bottle 2     -   16.4 Partial pre-clamping of the bottle 2 e.g. to the pressure         P2     -   16.5 Pre-clamping of the bottle 2 to the clamping or filling         pressure P1     -   16.6 Fast filling, slow filling and steadying     -   16.7 Pre-relief, for example to the pressure P2     -   16.8 Residual relief to atmospheric pressure     -   16.9 End of the filling processes.

As mentioned above, the pressure profile during the filling process and, in particular, the pressure profile in the individual treatment phases determine the sequence of these phases and, for this purpose, critically determine the quality and the shelf life, in particular also the CO₂ and oxygen content of the filled product. By detecting the pressure profile 16, it is thus possible to check and monitor, but also to control the filling process or the treatment phases.

Given the plurality of the filling elements 6 of the filling machine 1, a direct pressure-dependent control of the filling element 6 is not possible, at least not with reasonable control requirements. Instead, it is necessary to perform the individual treatment phases of the filling process in a time-controlled manner, namely synchronous with the rotary motion of the rotor 4 and with treatment times saved in the computer 13, said times enabling a selection to be made, over time, including the selection of the valves of the electro-pneumatic control valve devices 12 and of the valve blocks 11. The treatment times or control times, which also include the particular time interval between the discontinuation of a control signal and the actual complete switching (e.g. opening or closing) of a valve, are thus—for example—selected such that, also giving particular consideration to the volume of the bottles 2 and the pressure of the medium used for the particular treatment phase, the particular aimed-for result of the treatment phase concerned can be achieved as much as possible.

To monitor this time control of the treatment phases of the filling process and to adapt it to the ideal pressure profile of the filling process as optimally as possible, the real actual pressure profile 16 is measured at the filling positions 8 equipped with the pressure sensor 14 and saved at least temporarily in the computer 13. This actual pressure profile 16 or actual data of this profile can then be compared for example with a nominal pressure profile ideal for the filling material concerned and for the type of the bottles 2 and saved in the computer 13 or compared with corresponding nominal data. For clear deviations, i.e. deviations which exceed specified limit values, between the measured actual pressure profile and the nominal pressure profile in one or several treatment phases, the treatment times (beginning and/or end) of these treatment phases for all filling elements 6 of the filling machine 1 are then jointly changed such that the actual pressure profile corresponds to the nominal pressure profile with sufficient accuracy. With the new or corrected treatment times, the subsequent control of all filling elements 6 is then performed during the particular filling process. The correction, for example, is performed manually depending on the graphic representation on a picture monitor 17 of the computer 13 and/or automatically or controlled by computer. Furthermore, the corrected treatment times, for example, are saved in the computer 13 as treatment times typical of the type of bottles 2 and of the filling material concerned so that, for a subsequent fresh filling of the same bottles 2 or the same bottle type with the same filling material, these treatment times or this data can be drawn on for the control of the filling process.

In particular, there is the possibility of entering, for a first use of the filling machine 1 for filling bottles 2 of a certain type with a filling material of a certain type, the treatment times based on experience-related values at an operator monitor 17 with input keyboard into the computer 13. In a trial run of the filling machine 1, the entered treatment times are then corrected accordingly in the manner described above by comparison of the measured actual pressure profile with the nominal pressure profile and saved as reusable data typical of the type of container and filling material concerned in the computer 13. A plurality of other ways of controlling the filling machine 1 are possible with the design according to the invention.

REFERENCE SYMBOL List

-   1 filling machine -   2 bottle -   3 ring bowl -   3.1 liquid space -   3.2 gas space -   4 rotor -   5.1, 5.2 ring channel in the rotor 4 -   6 filling element -   7 container carrier -   8 filling position -   9 filling material discharge port -   10 gas port -   11 valve block -   12 electro-pneumatic control valve device -   13 computer -   14 pressure sensor -   15 measurement line -   16 pressure curve -   16.1-16.9 sections of the pressure curve 16 allocated to different     treatment phases -   17 operator monitor -   P1 clamping or filling pressure -   P2 reduced pre-relief pressure -   P3 vacuum 

1-11. (canceled)
 12. A method for pressure-filling a container with a liquid filling material using a filling system comprising at least one filling element group, said filling element group comprising a plurality of filling elements, wherein during a first treatment phase, said container is arranged in a sealed position at a filling element and pre-pressurized with an inert gas to one of a clamping pressure and a filling pressure, during a second treatment phase, said container is filled against said one of a pressure and a filling pressure, and during a third treatment phase following said second treatment phase, said container is relieved to ambient pressure, wherein at least one of treatment duration and treatment time of said treatment phases is determined by a timing control, and wherein, during all treatment phases, a pressure profile of an internal pressure of said container is detected, said method comprising with a pressure-measuring device, detecting a pressure profile of an internal pressure of said container only at a filling element of said filling element group, and based at least in part on said pressure profile, for all treatment phases of all filling elements of said filling element group, at least one of monitoring treatment duration, monitoring treatment time, correcting treatment duration, and correcting treatment time.
 13. The method of claim 12, further comprising comparing said pressure profile of said internal pressure of said container detected by said pressure-measuring device as an actual pressure profile with a nominal pressure profile for one of display of a sequence of treatment phase, monitoring of a sequence of treatment phase, change of treatment duration, change of treatment time, correction of treatment duration, and correction of treatment time.
 14. The method of claim 12, further comprising, prior to said first treatment phase, which serves to apply said one of a clamping pressure and a filling pressure to said containers, applying a further treatment phase in which said containers are at least one of evacuated and rinsed with an inert gas, and detecting said pressure profile of said internal pressure of said container during said further treatment phase.
 15. The method of claim 14, wherein said pressure during said further treatment phase is smaller than said one of a clamping pressure and a filling pressure.
 16. The method of claim 12, further comprising, during said second treatment phase, during which said container is filled, detecting a pressure profile of an internal pressure.
 17. The method of claim 12, further comprising providing said pressure measuring device at one filling position of a rotary filling machine having a plurality of filling positions, each of which comprises a filling element at a rotor that is driven to rotate about a vertical machine axis.
 18. The method of claim 12, further comprising providing said pressure measuring device at two diametrically opposed filling positions in relation to a vertical machine axis of a rotary filling machine having a plurality of filling positions, each of which comprises a filling element at a rotor that is driven to rotate about said vertical machine axis.
 19. The method of claim 12, further comprising saving, in a computer of said filling system, one of container specific data and product specific data for fresh use, said one of container specific data and product specific data comprising one of changed treatment duration, corrected treatment duration, changed treatment time, and corrected treatment time.
 20. An apparatus comprising a filling system for pressure-filling containers with a liquid filling material in one filling process with at least one filling element group comprising a plurality of filling elements for filling said containers against one of a clamping pressure and a filling pressure, wherein said containers, in a first treatment phase, are pre-pressurized by an inert gas to said one of a clamping pressure and filling pressure, and in a second treatment phase, said containers are filled to said one of a clamping pressure and a filling pressure, and in a third phase after said second phase, said containers are relieved to ambient pressure, wherein a control device provides timing control of one of treatment duration of said treatment phases and treatment time of said treatment phases, and wherein a pressure profile of internal pressure of said container during said treatment phases of said filling process is detected, said apparatus comprising a single pressure-measuring device for detecting a pressure profile for all filling elements, and a control device for at least one of monitoring and correcting one of treatment duration and treatment times of all treatment phases of all filling elements of said filling element group based on a pressure profile detected by said pressure-measuring device.
 21. The apparatus of claim 20, further comprising one of a control device and a computer, said one of a control device and a computer being configured for comparing an actual pressure profile of said internal pressure of said container detected by said pressure-measuring device with a nominal pressure profile for at least one of displaying a sequence of treatment phase, monitoring a sequence of treatment phase, changing a treatment time, changing a treatment duration, correcting a treatment time, and correcting a treatment duration.
 22. The apparatus of claim 20, wherein said pressure-measuring device is configured for detecting said pressure profile of said internal pressure of said container during all treatment phases, and wherein said control device is configured for one of correcting treatment times of all treatment phases based at least in part on said pressure profile, and correcting treatment duration of all treatment phases based at least in part on said pressure profile.
 23. The apparatus of claim 20, wherein said pressure measuring device is provided at one filling position of a rotary filling machine having a plurality of filling positions, each of which comprises a filling element at a rotor that is driven to rotate about said vertical machine axis.
 24. The apparatus of claim 20, wherein said pressure measuring device is provided at two diametrically opposed filling positions in relation to a vertical machine axis of a rotary filling machine having a plurality of filling positions, each of which comprises a filling element at a rotor that is driven to rotate about said vertical machine axis.
 25. The apparatus of claim 20, wherein said control device is configured for one of saving a particular changed treatment time, saving a particular changed treatment duration, saving a particular corrected treatment time, and saving a particular corrected treatment duration. 